1. Field of the Invention
The present invention is directed to clarifiers and more particularly, to a clarifier that utilizes a rotating cover sealingly engaged to the clarifier tank so as to eliminate foul air contamination of the environment.
2. Description of Related Art
Growing environmental awareness and environmental laws and regulations have lead to an increasing demand for enclosure and treatment of obnoxious or foul smells and odors in order to prevent these smells or odors from permeating the surrounding environment or atmosphere. Such environmental awareness, laws and regulations have had a serious impact on many industries.
Clarifiers are typically utilized in many industrial processes. A clarifier is a continuously operating, mechanically cleaned sedimentation device. Sedimentation is the process of subsidence and deposition of suspended matter carried by water, wastewater, or other liquids, by gravity. Feed is piped into an influent well which is semi-submerged and centrally positioned within a tank. The influent may be a liquid, slurry or other form of input material to a process or specific unit operation. Feed then flows outward to the periphery of the tank where effluent, i.e. any stream flowing out from a plant, process, basin or treatment device, is collected in a continuous peripheral launder or an open chute or trough for conveying solids, liquids or solutions by gravity. Settled solids are raked toward the center of the tank and into a discharge sump. Conventional traction clarifiers normally consist of a traction bridge which spans from a support member positioned in the center of the tank to the tank periphery and supports a raking mechanism, the influent well and a drive mechanism. The center support member consist of a tripod-like structure positioned upon the tank floor. The bridge is supported on a center bearing mounted on the top of the tripod-like structure. The end of the bridge adjacent the tank periphery is supported on a traction carriage. A drive mechanism, typically a geared motor, drives one of the traction wheels so as to rotate the bridge and raking mechanism. Power to the drive mechanism is supplied by a contactor column that is situated above the center bearing. A power supply cable is typically disposed beneath the tank floor and within the center bearing and contactor column. It has been found that due to the presence of the rotating traction bridge and the traction carriage, it is difficult to sufficiently cover the tank so as to prevent the foul or obnoxious air within the tank from contaminating or escaping into the surrounding environment or atmosphere.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide a new and improved clarifier that utilizes a rotating tank cover that prevents foul air within the tank from contaminating the surrounding environment and/or atmosphere and eliminates the need for the rotating traction bridge, tripod, central contactor column and associated center bearing.
It is another object of the present invention to provide a new and improved clarifier that can be manufactured at a reasonable cost.